• 1. Both take up too much space on the bed.
• 2. Both have irrational fears about vacuum cleaning.
• 3. Both mark their territory.
• 4. Neither tells you what's bothering them.
• 5. The smaller ones tend to be more nervous.
• 6. Both have an inordinate fascination with women's crotches.
• 7. Neither does any dishes.
• 8. Both fart shamelessly.
• 9. Neither of them notice when you get your hair cut.
• 10. Both like dominance games.
• 11. Both are suspicious of the postman.
• 12. Neither understands what you see in cats.